Prach configuration on nr-u

ABSTRACT

Physical random access channel (PRACH) configuration on new radio unlicensed (NR-U) networks is disclosed. A UE may perform PRACH transmission either with a transmission opportunity (TXOP) or outside of a TXOP. The UE monitors for a control signal, such as a preamble or common control signal, identifying a TXOP. The UE may obtain an autonomous random access configuration for communications outside of the current TXOP that identifies a random access slot includes a plurality of random access occasions. If the UE fails to detect the control signal, it transmits an autonomous random access signal in a random access occasion corresponding to a beam direction of its location in relation to the base station. Otherwise, upon detection of the control signal and receipt of a trigger signal, the UE may transmit a random access request within the TXOP.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/628,047, entitled, “PRACH CONFIGURATION ON NR-U,”filed on Feb. 8, 2018, which is expressly incorporated by referenceherein in its entirety.

BACKGROUND Field

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to physical random accesschannel (PRACH) configuration on new radio unlicensed (NR-U) networks.

Background

Wireless communication networks are widely deployed to provide variouscommunication services such as voice, video, packet data, messaging,broadcast, and the like. These wireless networks may be multiple-accessnetworks capable of supporting multiple users by sharing the availablenetwork resources. Such networks, which are usually multiple accessnetworks, support communications for multiple users by sharing theavailable network resources. One example of such a network is theUniversal Terrestrial Radio Access Network (UTRAN). The UTRAN is theradio access network (RAN) defined as a part of the Universal MobileTelecommunications System (UMTS), a third generation (3G) mobile phonetechnology supported by the 3rd Generation Partnership Project (3GPP).Examples of multiple-access network formats include Code DivisionMultiple Access (CDMA) networks, Time Division Multiple Access (TDMA)networks, Frequency Division Multiple Access (FDMA) networks, OrthogonalFDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.

A wireless communication network may include a number of base stationsor node Bs that can support communication for a number of userequipments (UEs). A UE may communicate with a base station via downlinkand uplink. The downlink (or forward link) refers to the communicationlink from the base station to the UE, and the uplink (or reverse link)refers to the communication link from the UE to the base station.

A base station may transmit data and control information on the downlinkto a UE and/or may receive data and control information on the uplinkfrom the UE. On the downlink, a transmission from the base station mayencounter interference due to transmissions from neighbor base stationsor from other wireless radio frequency (RF) transmitters. On the uplink,a transmission from the UE may encounter interference from uplinktransmissions of other UEs communicating with the neighbor base stationsor from other wireless RF transmitters. This interference may degradeperformance on both the downlink and uplink.

As the demand for mobile broadband access continues to increase, thepossibilities of interference and congested networks grows with more UEsaccessing the long-range wireless communication networks and moreshort-range wireless systems being deployed in communities. Research anddevelopment continue to advance wireless technologies not only to meetthe growing demand for mobile broadband access, but to advance andenhance the user experience with mobile communications.

SUMMARY

In one aspect of the disclosure, a method of wireless communicationincludes monitoring, by a UE, for a control signal from a serving basestation, wherein the control signal identifies a current transmissionopportunity (TXOP) of the serving base station, obtaining, by the UE, anautonomous random access configuration for communications outside of thecurrent TXOP, wherein the autonomous random access configurationidentifies a random access slot that includes a plurality of randomaccess occasions, and transmitting, by the UE, in response to a failureto detect the control signal an autonomous random access signal in arandom access occasion of the plurality of random access occasionscorresponding to a synchronization signal block (SSB) identified by theUE for transmission.

In an additional aspect of the disclosure, an apparatus configured forwireless communication includes means for monitoring, by a UE, for acontrol signal from a serving base station, wherein the control signalidentifies a current TXOP of the serving base station, means forobtaining, by the UE, an autonomous random access configuration forcommunications outside of the current TXOP, wherein the autonomousrandom access configuration identifies a random access slot thatincludes a plurality of random access occasions, and means fortransmitting, by the UE, in response to a failure to detect the controlsignal an autonomous random access signal in a random access occasion ofthe plurality of random access occasions corresponding to an SSBidentified by the UE for transmission.

In an additional aspect of the disclosure, a non-transitorycomputer-readable medium having program code recorded thereon. Theprogram code further includes code to monitor, by a UE, for a controlsignal from a serving base station, wherein the control signalidentifies a current TXOP of the serving base station, code to obtain,by the UE, an autonomous random access configuration for communicationsoutside of the current TXOP, wherein the autonomous random accessconfiguration identifies a random access slot that includes a pluralityof random access occasions, and code to transmit, by the UE, in responseto a failure to detect the control signal an autonomous random accesssignal in a random access occasion of the plurality of random accessoccasions corresponding to an SSB identified by the UE for transmission.

In an additional aspect of the disclosure, an apparatus configured forwireless communication is disclosed. The apparatus includes at least oneprocessor, and a memory coupled to the processor. The processor isconfigured to monitor, by a UE, for a control signal from a serving basestation, wherein the control signal identifies a current TXOP of theserving base station, to obtain, by the UE, an autonomous random accessconfiguration for communications outside of the current TXOP, whereinthe autonomous random access configuration identifies a random accessslot that includes a plurality of random access occasions, and totransmit, by the UE, in response to a failure to detect the controlsignal an autonomous random access signal in a random access occasion ofthe plurality of random access occasions corresponding to an SSBidentified by the UE for transmission.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presentdisclosure may be realized by reference to the following drawings. Inthe appended figures, similar components or features may have the samereference label. Further, various components of the same type may bedistinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1 is a block diagram illustrating details of a wirelesscommunication system.

FIG. 2 is a block diagram illustrating a design of a base station and aUE configured according to one aspect of the present disclosure.

FIG. 3 is a block diagram illustrating a wireless communication systemincluding base stations that use directional wireless beams.

FIG. 4 is a block diagram illustrating example blocks executed toimplement one aspect of the present disclosure.

FIG. 5 is a block diagram illustrating a base station and UE configuredaccording to one aspect of the present disclosure.

FIGS. 6A and 6B are block diagrams illustrating a base station and UEconfigured according to aspects of the present disclosure.

FIG. 7 is a block diagram illustrating a base station and UE configuredaccording to one aspect of the present disclosure.

FIG. 8 is a block diagram illustrating a base station and UE configuredaccording to one aspect of the present disclosure.

FIG. 9 is a block diagram illustrating detail of a UE configuredaccording to aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to limit the scope of the disclosure.Rather, the detailed description includes specific details for thepurpose of providing a thorough understanding of the inventive subjectmatter. It will be apparent to those skilled in the art that thesespecific details are not required in every case and that, in someinstances, well-known structures and components are shown in blockdiagram form for clarity of presentation.

This disclosure relates generally to providing or participating inauthorized shared access between two or more wireless communicationssystems, also referred to as wireless communications networks. Invarious embodiments, the techniques and apparatus may be used forwireless communication networks such as code division multiple access(CDMA) networks, time division multiple access (TDMA) networks,frequency division multiple access (FDMA) networks, orthogonal FDMA(OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks,GSM networks, 5^(th) Generation (5G) or new radio (NR) networks, as wellas other communications networks. As described herein, the terms“networks” and “systems” may be used interchangeably.

An OFDMA network may implement a radio technology such as evolved UTRA(E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and thelike. UTRA, E-UTRA, and Global System for Mobile Communications (GSM)are part of universal mobile telecommunication system (UMTS). Inparticular, long term evolution (LTE) is a release of UMTS that usesE-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documentsprovided from an organization named “3rd Generation Partnership Project”(3GPP), and cdma2000 is described in documents from an organizationnamed “3rd Generation Partnership Project 2” (3GPP2). These variousradio technologies and standards are known or are being developed. Forexample, the 3rd Generation Partnership Project (3GPP) is acollaboration between groups of telecommunications associations thataims to define a globally applicable third generation (3G) mobile phonespecification. 3GPP long term evolution (LTE) is a 3GPP project whichwas aimed at improving the universal mobile telecommunications system(UMTS) mobile phone standard. The 3GPP may define specifications for thenext generation of mobile networks, mobile systems, and mobile devices.The present disclosure is concerned with the evolution of wirelesstechnologies from LTE, 4G, 5G, NR, and beyond with shared access towireless spectrum between networks using a collection of new anddifferent radio access technologies or radio air interfaces.

In particular, 5G networks contemplate diverse deployments, diversespectrum, and diverse services and devices that may be implemented usingan OFDM-based unified, air interface. In order to achieve these goals,further enhancements to LTE and LTE-A are considered in addition todevelopment of the new radio technology for 5G NR networks. The 5G NRwill be capable of scaling to provide coverage (1) to a massive Internetof things (IoTs) with an ultra-high density (e.g., ˜1M nodes/km²),ultra-low complexity (e.g., ˜10s of bits/sec), ultra-low energy (e.g.,˜10+ years of battery life), and deep coverage with the capability toreach challenging locations; (2) including mission-critical control withstrong security to safeguard sensitive personal, financial, orclassified information, ultra-high reliability (e.g., ˜99.9999%reliability), ultra-low latency (e.g., ˜1 ms), and users with wideranges of mobility or lack thereof; and (3) with enhanced mobilebroadband including extreme high capacity (e.g., ˜10 Tbps/km²), extremedata rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates),and deep awareness with advanced discovery and optimizations.

The 5G NR may be implemented to use optimized OFDM-based waveforms withscalable numerology and transmission time interval (TTI); having acommon, flexible framework to efficiently multiplex services andfeatures with a dynamic, low-latency time division duplex(TDD)/frequency division duplex (FDD) design; and with advanced wirelesstechnologies, such as massive multiple input, multiple output (MIMO),robust millimeter wave (mmWave) transmissions, advanced channel coding,and device-centric mobility. Scalability of the numerology in 5G NR,with scaling of subcarrier spacing, may efficiently address operatingdiverse services across diverse spectrum and diverse deployments. Forexample, in various outdoor and macro coverage deployments of less than3 GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz,for example over 1, 5, 10, 20 MHz, and the like bandwidth. For othervarious outdoor and small cell coverage deployments of TDD greater than3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHzbandwidth. For other various indoor wideband implementations, using aTDD over the unlicensed portion of the 5 GHz band, the subcarrierspacing may occur with 60 kHz over a 160 MHz bandwidth. Finally, forvarious deployments transmitting with mmWave components at a TDD of 28GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz bandwidth.

The scalable numerology of the 5G NR facilitates scalable TTI fordiverse latency and quality of service (QoS) requirements. For example,shorter TTI may be used for low latency and high reliability, whilelonger TTI may be used for higher spectral efficiency. The efficientmultiplexing of long and short TTIs to allow transmissions to start onsymbol boundaries. 5G NR also contemplates a self-contained integratedsubframe design with uplink/downlink scheduling information, data, andacknowledgement in the same subframe. The self-contained integratedsubframe supports communications in unlicensed or contention-basedshared spectrum, adaptive uplink/downlink that may be flexiblyconfigured on a per-cell basis to dynamically switch between uplink anddownlink to meet the current traffic needs.

Various other aspects and features of the disclosure are furtherdescribed below. It should be apparent that the teachings herein may beembodied in a wide variety of forms and that any specific structure,function, or both being disclosed herein is merely representative andnot limiting. Based on the teachings herein one of an ordinary level ofskill in the art should appreciate that an aspect disclosed herein maybe implemented independently of any other aspects and that two or moreof these aspects may be combined in various ways. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, such an apparatusmay be implemented or such a method may be practiced using otherstructure, functionality, or structure and functionality in addition toor other than one or more of the aspects set forth herein. For example,a method may be implemented as part of a system, device, apparatus,and/or as instructions stored on a computer readable medium forexecution on a processor or computer. Furthermore, an aspect maycomprise at least one element of a claim.

FIG. 1 is a block diagram illustrating 5G network 100 including variousbase stations and UEs configured according to aspects of the presentdisclosure. The 5G network 100 includes a number of base stations 105and other network entities. A base station may be a station thatcommunicates with the UEs and may also be referred to as an evolved nodeB (eNB), a next generation eNB (gNB), an access point, and the like.Each base station 105 may provide communication coverage for aparticular geographic area. In 3GPP, the term “cell” can refer to thisparticular geographic coverage area of a base station and/or a basestation subsystem serving the coverage area, depending on the context inwhich the term is used.

A base station may provide communication coverage for a macro cell or asmall cell, such as a pico cell or a femto cell, and/or other types ofcell. A macro cell generally covers a relatively large geographic area(e.g., several kilometers in radius) and may allow unrestricted accessby UEs with service subscriptions with the network provider. A smallcell, such as a pico cell, would generally cover a relatively smallergeographic area and may allow unrestricted access by UEs with servicesubscriptions with the network provider. A small cell, such as a femtocell, would also generally cover a relatively small geographic area(e.g., a home) and, in addition to unrestricted access, may also providerestricted access by UEs having an association with the femto cell(e.g., UEs in a closed subscriber group (CSG), UEs for users in thehome, and the like). A base station for a macro cell may be referred toas a macro base station. A base station for a small cell may be referredto as a small cell base station, a pico base station, a femto basestation or a home base station. In the example shown in FIG. 1, the basestations 105 d and 105 e are regular macro base stations, while basestations 105 a-105 c are macro base stations enabled with one of 3dimension (3D), full dimension (FD), or massive MIMO. Base stations 105a-105 c take advantage of their higher dimension MIMO capabilities toexploit 3D beamforming in both elevation and azimuth beamforming toincrease coverage and capacity. Base station 105 f is a small cell basestation which may be a home node or portable access point. A basestation may support one or multiple (e.g., two, three, four, and thelike) cells.

The 5G network 100 may support synchronous or asynchronous operation.For synchronous operation, the base stations may have similar frametiming, and transmissions from different base stations may beapproximately aligned in time. For asynchronous operation, the basestations may have different frame timing, and transmissions fromdifferent base stations may not be aligned in time.

The UEs 115 are dispersed throughout the wireless network 100, and eachUE may be stationary or mobile. A UE may also be referred to as aterminal, a mobile station, a subscriber unit, a station, or the like. AUE may be a cellular phone, a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, atablet computer, a laptop computer, a cordless phone, a wireless localloop (WLL) station, or the like. In one aspect, a UE may be a devicethat includes a Universal Integrated Circuit Card (UICC). In anotheraspect, a UE may be a device that does not include a UICC. In someaspects, UEs that do not include UICCs may also be referred to asinternet of everything (IoE) devices. UEs 115 a-115 d are examples ofmobile smart phone-type devices accessing 5G network 100 A UE may alsobe a machine specifically configured for connected communication,including machine type communication (MTC), enhanced MTC (eMTC),narrowband IoT (NB-IoT) and the like. UEs 115 e-115 k are examples ofvarious machines configured for communication that access 5G network100. A UE may be able to communicate with any type of the base stations,whether macro base station, small cell, or the like. In FIG. 1, alightning bolt (e.g., communication links) indicates wirelesstransmissions between a UE and a serving base station, which is a basestation designated to serve the UE on the downlink and/or uplink, ordesired transmission between base stations, and backhaul transmissionsbetween base stations.

In operation at 5G network 100, base stations 105 a-105 c serve UEs 115a and 115 b using 3D beamforming and coordinated spatial techniques,such as coordinated multipoint (CoMP) or multi-connectivity. Macro basestation 105 d performs backhaul communications with base stations 105a-105 c, as well as small cell, base station 105 f. Macro base station105 d also transmits multicast services which are subscribed to andreceived by UEs 115 c and 115 d. Such multicast services may includemobile television or stream video, or may include other services forproviding community information, such as weather emergencies or alerts,such as Amber alerts or gray alerts.

5G network 100 also support mission critical communications withultra-reliable and redundant links for mission critical devices, such UE115 e, which is a drone. Redundant communication links with UE 115 einclude from macro base stations 105 d and 105 e, as well as small cellbase station 105 f. Other machine type devices, such as UE 115 f(thermometer), UE 115 g (smart meter), and UE 115 h (wearable device)may communicate through 5G network 100 either directly with basestations, such as small cell base station 105 f, and macro base station105 e, or in multi-hop configurations by communicating with another userdevice which relays its information to the network, such as UE 115 fcommunicating temperature measurement information to the smart meter, UE115 g, which is then reported to the network through small cell basestation 105 f. 5G network 100 may also provide additional networkefficiency through dynamic, low-latency TDD/FDD communications, such asin a vehicle-to-vehicle (V2V) mesh network between UEs 115 i-115 kcommunicating with macro base station 105 e.

FIG. 2 shows a block diagram of a design of a base station 105 and a UE115, which may be one of the base station and one of the UEs in FIG. 1.At the base station 105, a transmit processor 220 may receive data froma data source 212 and control information from a controller/processor240. The control information may be for the PBCH, PCFICH, PHICH, PDCCH,EPDCCH, MPDCCH etc. The data may be for the PDSCH, etc. The transmitprocessor 220 may process (e.g., encode and symbol map) the data andcontrol information to obtain data symbols and control symbols,respectively. The transmit processor 220 may also generate referencesymbols, e.g., for the PSS, SSS, and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 230 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODs) 232 a through 232t. Each modulator 232 may process a respective output symbol stream(e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator232 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal.Downlink signals from modulators 232 a through 232 t may be transmittedvia the antennas 234 a through 234 t, respectively.

At the UE 115, the antennas 252 a through 252 r may receive the downlinksignals from the base station 105 and may provide received signals tothe demodulators (DEMODs) 254 a through 254 r, respectively. Eachdemodulator 254 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 254 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 256 may obtainreceived symbols from all the demodulators 254 a through 254 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 258 may process (e.g., demodulate,deinterleave, and decode) the detected symbols, provide decoded data forthe UE 115 to a data sink 260, and provide decoded control informationto a controller/processor 280.

On the uplink, at the UE 115, a transmit processor 264 may receive andprocess data (e.g., for the PUSCH) from a data source 262 and controlinformation (e.g., for the PUCCH) from the controller/processor 280. Thetransmit processor 264 may also generate reference symbols for areference signal. The symbols from the transmit processor 264 may beprecoded by a TX MIMO processor 266 if applicable, further processed bythe modulators 254 a through 254 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 105. At the base station 105, the uplinksignals from the UE 115 may be received by the antennas 234, processedby the demodulators 232, detected by a MIMO detector 236 if applicable,and further processed by a receive processor 238 to obtain decoded dataand control information sent by the UE 115. The processor 238 mayprovide the decoded data to a data sink 239 and the decoded controlinformation to the controller/processor 240.

The controllers/processors 240 and 280 may direct the operation at thebase station 105 and the UE 115, respectively. The controller/processor240 and/or other processors and modules at the base station 105 mayperform or direct the execution of various processes for the techniquesdescribed herein. The controllers/processor 280 and/or other processorsand modules at the UE 115 may also perform or direct the execution ofthe functional blocks illustrated in FIG. 4, and/or other processes forthe techniques described herein. The memories 242 and 282 may store dataand program codes for the base station 105 and the UE 115, respectively.A scheduler 244 may schedule UEs for data transmission on the downlinkand/or uplink.

Wireless communications systems operated by different network operatingentities (e.g., network operators) may share spectrum. In someinstances, a network operating entity may be configured to use anentirety of a designated shared spectrum for at least a period of timebefore another network operating entity uses the entirety of thedesignated shared spectrum for a different period of time. Thus, inorder to allow network operating entities use of the full designatedshared spectrum, and in order to mitigate interfering communicationsbetween the different network operating entities, certain resources(e.g., time) may be partitioned and allocated to the different networkoperating entities for certain types of communication.

For example, a network operating entity may be allocated certain timeresources reserved for exclusive communication by the network operatingentity using the entirety of the shared spectrum. The network operatingentity may also be allocated other time resources where the entity isgiven priority over other network operating entities to communicateusing the shared spectrum. These time resources, prioritized for use bythe network operating entity, may be utilized by other network operatingentities on an opportunistic basis if the prioritized network operatingentity does not utilize the resources. Additional time resources may beallocated for any network operator to use on an opportunistic basis.

Access to the shared spectrum and the arbitration of time resourcesamong different network operating entities may be centrally controlledby a separate entity, autonomously determined by a predefinedarbitration scheme, or dynamically determined based on interactionsbetween wireless nodes of the network operators.

In some cases, UE 115 and base station 105 may operate in a shared radiofrequency spectrum band, which may include licensed or unlicensed (e.g.,contention-based) frequency spectrum. In an unlicensed frequency portionof the shared radio frequency spectrum band, UEs 115 or base stations105 may traditionally perform a medium-sensing procedure to contend foraccess to the frequency spectrum. For example, UE 115 or base station105 may perform a listen before talk (LBT) procedure such as a clearchannel assessment (CCA) prior to communicating in order to determinewhether the shared channel is available. A CCA may include an energydetection procedure to determine whether there are any other activetransmissions. For example, a device may infer that a change in areceived signal strength indicator (RSSI) of a power meter indicatesthat a channel is occupied. Specifically, signal power that isconcentrated in a certain bandwidth and exceeds a predetermined noisefloor may indicate another wireless transmitter. A CCA also may includedetection of specific sequences that indicate use of the channel. Forexample, another device may transmit a specific preamble prior totransmitting a data sequence. In some cases, an LBT procedure mayinclude a wireless node adjusting its own backoff window based on theamount of energy detected on a channel and/or theacknowledge/negative-acknowledge (ACK/NACK) feedback for its owntransmitted packets as a proxy for collisions.

Use of a medium-sensing procedure to contend for access to an unlicensedshared spectrum may result in communication inefficiencies. This may beparticularly evident when multiple network operating entities (e.g.,network operators) are attempting to access a shared resource. In 5Gnetwork 100, base stations 105 and UEs 115 may be operated by the sameor different network operating entities. In some examples, an individualbase station 105 or UE 115 may be operated by more than one networkoperating entity. In other examples, each base station 105 and UE 115may be operated by a single network operating entity. Requiring eachbase station 105 and UE 115 of different network operating entities tocontend for shared resources may result in increased signaling overheadand communication latency.

FIG. 3 illustrates an example of a timing diagram 300 for coordinatedresource partitioning. The timing diagram 300 includes a superframe 305,which may represent a fixed duration of time (e.g., 20 ms). Superframe305 may be repeated for a given communication session and may be used bya wireless system such as 5G network 100 described with reference toFIG. 1. The superframe 305 may be divided into intervals such as anacquisition interval (A-INT) 310 and an arbitration interval 315. Asdescribed in more detail below, the A-NT 310 and arbitration interval315 may be subdivided into sub-intervals, designated for certainresource types, and allocated to different network operating entities tofacilitate coordinated communications between the different networkoperating entities. For example, the arbitration interval 315 may bedivided into a plurality of sub-intervals 320. Also, the superframe 305may be further divided into a plurality of subframes 325 with a fixedduration (e.g., 1 ms). While timing diagram 300 illustrates threedifferent network operating entities (e.g., Operator A, Operator B,Operator C), the number of network operating entities using thesuperframe 305 for coordinated communications may be greater than orfewer than the number illustrated in timing diagram 300.

The A-INT 310 may be a dedicated interval of the superframe 305 that isreserved for exclusive communications by the network operating entities.In some examples, each network operating entity may be allocated certainresources within the A-INT 310 for exclusive communications. Forexample, resources 330-a may be reserved for exclusive communications byOperator A, such as through base station 105 a, resources 330-b may bereserved for exclusive communications by Operator B, such as throughbase station 105 b, and resources 330-c may be reserved for exclusivecommunications by Operator C, such as through base station 105 c. Sincethe resources 330-a are reserved for exclusive communications byOperator A, neither Operator B nor Operator C can communicate duringresources 330-a, even if Operator A chooses not to communicate duringthose resources. That is, access to exclusive resources is limited tothe designated network operator. Similar restrictions apply to resources330-b for Operator B and resources 330-c for Operator C. The wirelessnodes of Operator A (e.g, UEs 115 or base stations 105) may communicateany information desired during their exclusive resources 330-a, such ascontrol information or data.

When communicating over an exclusive resource, a network operatingentity does not need to perform any medium sensing procedures (e.g.,listen-before-talk (LBT) or clear channel assessment (CCA)) because thenetwork operating entity knows that the resources are reserved. Becauseonly the designated network operating entity may communicate overexclusive resources, there may be a reduced likelihood of interferingcommunications as compared to relying on medium sensing techniques alone(e.g., no hidden node problem). In some examples, the A-INT 310 is usedto transmit control information, such as synchronization signals (e.g.,SYNC signals), system information (e.g., system information blocks(SIBs)), paging information (e.g., physical broadcast channel (PBCH)messages), or random access information (e.g., random access channel(RACH) signals). In some examples, all of the wireless nodes associatedwith a network operating entity may transmit at the same time duringtheir exclusive resources.

In some examples, resources may be classified as prioritized for certainnetwork operating entities. Resources that are assigned with priorityfor a certain network operating entity may be referred to as aguaranteed interval (G-INT) for that network operating entity. Theinterval of resources used by the network operating entity during theG-INT may be referred to as a prioritized sub-interval. For example,resources 335-a may be prioritized for use by Operator A and maytherefore be referred to as a G-INT for Operator A (e.g., G-INT-OpA).Similarly, resources 335-b may be prioritized for Operator B, resources335-c may be prioritized for Operator C, resources 335-d may beprioritized for Operator A, resources 335-e may be prioritized forOperator B, and resources 335-f may be prioritized for operator C.

The various G-INT resources illustrated in FIG. 3 appear to be staggeredto illustrate their association with their respective network operatingentities, but these resources may all be on the same frequencybandwidth. Thus, if viewed along a time-frequency grid, the G-INTresources may appear as a contiguous line within the superframe 305.This partitioning of data may be an example of time divisionmultiplexing (TDM). Also, when resources appear in the same sub-interval(e.g., resources 340-a and resources 335-b), these resources representthe same time resources with respect to the superframe 305 (e.g., theresources occupy the same sub-interval 320), but the resources areseparately designated to illustrate that the same time resources can beclassified differently for different operators.

When resources are assigned with priority for a certain networkoperating entity (e.g., a G-INT), that network operating entity maycommunicate using those resources without having to wait or perform anymedium sensing procedures (e.g., LBT or CCA). For example, the wirelessnodes of Operator A are free to communicate any data or controlinformation during resources 335-a without interference from thewireless nodes of Operator B or Operator C.

A network operating entity may additionally signal to another operatorthat it intends to use a particular G-INT. For example, referring toresources 335-a, Operator A may signal to Operator B and Operator C thatit intends to use resources 335-a. Such signaling may be referred to asan activity indication. Moreover, since Operator A has priority overresources 335-a, Operator A may be considered as a higher priorityoperator than both Operator B and Operator C. However, as discussedabove, Operator A does not have to send signaling to the other networkoperating entities to ensure interference-free transmission duringresources 335-a because the resources 335-a are assigned with priorityto Operator A.

Similarly, a network operating entity may signal to another networkoperating entity that it intends not to use a particular G-INT. Thissignaling may also be referred to as an activity indication. Forexample, referring to resources 335-b, Operator B may signal to OperatorA and Operator C that it intends not to use the resources 335-b forcommunication, even though the resources are assigned with priority toOperator B. With reference to resources 335-b, Operator B may beconsidered a higher priority network operating entity than Operator Aand Operator C. In such cases, Operators A and C may attempt to useresources of sub-interval 320 on an opportunistic basis. Thus, from theperspective of Operator A, the sub-interval 320 that contains resources335-b may be considered an opportunistic interval (O-INT) for Operator A(e.g., O-INT-OpA). For illustrative purposes, resources 340-a mayrepresent the O-INT for Operator A. Also, from the perspective ofOperator C, the same sub-interval 320 may represent an O-INT forOperator C with corresponding resources 340-b. Resources 340-a, 335-b,and 340-b all represent the same time resources (e.g., a particularsub-interval 320), but are identified separately to signify that thesame resources may be considered as a G-INT for some network operatingentities and yet as an O-INT for others.

To utilize resources on an opportunistic basis, Operator A and OperatorC may perform medium-sensing procedures to check for communications on aparticular channel before transmitting data. For example, if Operator Bdecides not to use resources 335-b (e.g., G-INT-OpB), then Operator Amay use those same resources (e.g., represented by resources 340-a) byfirst checking the channel for interference (e.g., LBT) and thentransmitting data if the channel was determined to be clear. Similarly,if Operator C wanted to access resources on an opportunistic basisduring sub-interval 320 (e.g., use an O-INT represented by resources340-b) in response to an indication that Operator B was not going to useits G-INT, Operator C may perform a medium sensing procedure and accessthe resources if available. In some cases, two operators (e.g., OperatorA and Operator C) may attempt to access the same resources, in whichcase the operators may employ contention-based procedures to avoidinterfering communications. The operators may also have sub-prioritiesassigned to them designed to determine which operator may gain access toresources if more than operator is attempting access simultaneously.

In some examples, a network operating entity may intend not to use aparticular G-INT assigned to it, but may not send out an activityindication that conveys the intent not to use the resources. In suchcases, for a particular sub-interval 320, lower priority operatingentities may be configured to monitor the channel to determine whether ahigher priority operating entity is using the resources. If a lowerpriority operating entity determines through LBT or similar method thata higher priority operating entity is not going to use its G-INTresources, then the lower priority operating entities may attempt toaccess the resources on an opportunistic basis as described above.

In some examples, access to a G-INT or O-INT may be preceded by areservation signal (e.g., request-to-send (RTS)/clear-to-send (CTS)),and the contention window (CW) may be randomly chosen between one andthe total number of operating entities.

In some examples, an operating entity may employ or be compatible withcoordinated multipoint (CoMP) communications. For example an operatingentity may employ CoMP and dynamic time division duplex (TDD) in a G-INTand opportunistic CoMP in an O-INT as needed.

In the example illustrated in FIG. 3, each sub-interval 320 includes aG-INT for one of Operator A, B, or C. However, in some cases, one ormore sub-intervals 320 may include resources that are neither reservedfor exclusive use nor reserved for prioritized use (e.g., unassignedresources). Such unassigned resources may be considered an O-INT for anynetwork operating entity, and may be accessed on an opportunistic basisas described above.

In some examples, each subframe 325 may contain 14 symbols (e.g., 250-μsfor 60 kHz tone spacing). These subframes 325 may be standalone,self-contained Interval-Cs (ITCs) or the subframes 325 may be a part ofa long ITC. An ITC may be a self-contained transmission starting with adownlink transmission and ending with a uplink transmission. In someembodiments, an ITC may contain one or more subframes 325 operatingcontiguously upon medium occupation. In some cases, there may be amaximum of eight network operators in an A-INT 310 (e.g., with durationof 2 ms) assuming a 250-μs transmission opportunity.

Although three operators are illustrated in FIG. 3, it should beunderstood that fewer or more network operating entities may beconfigured to operate in a coordinated manner as described above. Insome cases, the location of the G-INT, O-INT, or A-INT within superframe305 for each operator is determined autonomously based on the number ofnetwork operating entities active in a system. For example, if there isonly one network operating entity, each sub-interval 320 may be occupiedby a G-INT for that single network operating entity, or thesub-intervals 320 may alternate between G-INTs for that networkoperating entity and O-INTs to allow other network operating entities toenter. If there are two network operating entities, the sub-intervals320 may alternate between G-INTs for the first network operating entityand G-INTs for the second network operating entity. If there are threenetwork operating entities, the G-INT and O-INTs for each networkoperating entity may be designed as illustrated in FIG. 3. If there arefour network operating entities, the first four sub-intervals 320 mayinclude consecutive G-INTs for the four network operating entities andthe remaining two sub-intervals 320 may contain O-INTs. Similarly, ifthere are five network operating entities, the first five sub-intervals320 may contain consecutive G-INTs for the five network operatingentities and the remaining sub-interval 320 may contain an O-INT. Ifthere are six network operating entities, all six sub-intervals 320 mayinclude consecutive G-INTs for each network operating entity. It shouldbe understood that these examples are for illustrative purposes only andthat other autonomously determined interval allocations may be used.

It should be understood that the coordination framework described withreference to FIG. 3 is for illustration purposes only. For example, theduration of superframe 305 may be more or less than 20 ms. Also, thenumber, duration, and location of sub-intervals 320 and subframes 325may differ from the configuration illustrated. Also, the types ofresource designations (e.g., exclusive, prioritized, unassigned) maydiffer or include more or less sub-designations.

In new radio (NR) networks, the physical random access channel (PRACH)time instance may be configured via a PRACH configuration indexcontained in the remaining material system information (RMSI)transmission. For a given PRACH configuration index, a UE may obtain thefollowing: the PRACH format; the configuration period and subframenumber; the number of RACH slots within a subframe and number of RACHoccasions within a RACH slot, and the start symbol index. In addition,the RMSI configures the SSB-to-RACH-resource mapping so that each SSBcan map to a corresponding PRACH occasion.

In NR unlicensed (NR-U) networks, each transmitting node would generallyperform a listen before talk (LBT) procedure before transmitting on theshared communication channel. Because of the unpredictability of LBTresults, if a PRACH occasion follows the NR configuration, it isuncertain whether a UE would be able to transmit at the configured PRACHoccasion. When a UE misses one configured PRACH occasion, it wouldgenerally wait until the next configured PRACH occasion corresponding tothe detected SSB. PRACH latency is expected to be higher due to LBToperations. One proposed solution to reduce the latency may be toincrease the PRACH occasions in time. However, this solution wouldresult in a cost of increased network overhead.

PRACH transmission can happen either within a base station transmissionopportunity (TXOP) or outside of the TXOP. The base station TXOP is theperiod in which the base station secures the shared medium forcommunications. PRACH configuration outside of base station TXOP can bereferred to as autonomous PRACH occasions and can follow NR or similarto NR procedures. Additionally, because the communication channels areshared, there may be cause to leave a gap between each PRACH occasion inwhich an LBT procedure may be performed. In current NR configurations,when multiple PRACH instances are allocated within a RACH slot, they arescheduled back-to-back without a gap. If gap is needed, a base stationmay schedule an LBT gap between each RACH occasion or, alternatively,the UE may autonomously shorten the PRACH duration in order to create agap for an LBT procedure. The PRACH configuration will serve as theintended base station reception with the corresponding beam.Additionally, an autonomous RACH window can be further added to reducethe system overhead. PRACH transmission within the TXOP can have acompletely different configuration. If a UE detects a preamble or commoncontrol signal (e.g., CPDCCH), the UE could be triggered to send RRACHwithin the TXOP. RACH configuration within the TXOP can overwrite theautonomous RACH configuration.

FIG. 4 is a block diagram illustrating example blocks executed toimplement one aspect of the present disclosure. The example blocks willalso be described with respect to UE 115 as illustrated in FIG. 9. FIG.9 is a block diagram illustrating UE 115 configured according to oneaspect of the present disclosure. UE 115 includes the structure,hardware, and components as illustrated for UE 115 of FIG. 2. Forexample, UE 115 includes controller/processor 280, which operates toexecute logic or computer instructions stored in memory 282, as well ascontrolling the components of UE 115 that provide the features andfunctionality of UE 115. UE 115, under control of controller/processor280, transmits and receives signals via wireless radios 900 a-r andantennas 252 a-r. Wireless radios 900 a-r includes various componentsand hardware, as illustrated in FIG. 2 for UE 115, includingmodulator/demodulators 254 a-r, MIMO detector 256, receive processor258, transmit processor 264, and TX MIMO processor 266.

At block 400, a UE monitors for a control signal from a serving basestation, wherein the control signal identifies a current TXOP of theserving base station. PRACH transmissions may occur either within oroutside of the TXOP. UE 115 will monitor for signaling that identifies acurrent TXOP. For example, under control of controller/processor 280, UE115 executes preamble detection logic 901, stored in memory 282. Theexecution environment of preamble detection logic 901 allows UE 115 tomonitor for the control signal identifying the current TXOP. Forexample, signals received via antennas 252 a-r and wireless radios 900a-r are decoded and check for preamble or CPDCCH.

At block 401, the UE obtains an autonomous random access configurationfor communications outside of the current TXOP, wherein the autonomousrandom access configuration identifies a random access slot thatincludes a plurality of random access occasions. In order to participatein PRACH transmissions outside of a TXOP, UE 115 will obtain anautonomous RACH configuration. The autonomous RACH configuration may besignaled from the serving base station. UE 115 stores the configurationin memory 282 at autonomous RACH configuration 902. The RACHconfiguration includes a PRACH slot with multiple PRACH occasionsavailable therein.

At block 402, the UE makes a determination whether the control signal isdetected. If not, then, at block 403, the UE transmits an autonomousrandom access signal in a random access occasion of the plurality ofrandom access occasions corresponding to a SSB identified by the UE fortransmission. When a PRACH transmission is to occur from UE 115, thefailure to detect a signal identifying the TXOP indicates that UE 115will transmit an autonomous PRACH outside of the TXOP. UE 115, undercontrol of controller/processor 280, executes PRACH generator 904, inmemory 282. The execution environment of PRACH generator 904 providesfor UE 115 to transmit a random access request via wireless radios 900a-r and antennas 252 a-r.

At block 404, if the UE detects the control signal, the UE receives adownlink control signal that includes a trigger signal to send a randomaccess signal. When UE 115 detects the control signal identifying thecurrent TXOP, UE 115 will perform PRACH transmissions within the TXOP. Atrigger signal is received at UE 115 via antennas 252 a-r and wirelessradios 900 a-r triggering PRACH transmission. The in-TXOP PRACH may bemade according to a different RACH configuration. UE 115 may receive thenew TXOP RACH configuration for in-TXOP PRACH transmissions. UE 115stores the configuration in memory 282 at TXOP RACH configuration 903.

At block 405, the UE transmits the random access signal in a TXOP randomaccess occasion. Within the execution environment of PRACH generator904, in response to the trigger signal, UE 115 generates and transmitsthe PRACH within the TXOP via wireless radios 900 a-r and antennas 252a-r.

FIG. 5 is a block diagram illustrating a base station 105 and UE 115configured according to one aspect of the present disclosure. For PRACHconfiguration outside of a TXOP, base station 105 will use the beamdirection for PRACH reception corresponding to the configuration withinan autonomous PRACH window 500 if base station 105 is not transmittingin downlink. In the illustrated example, base station 105 schedules oneRACH slot, RACH slots 501 and 502, every subframe. Each such RACH slotfurther includes scheduling of three RACH occasions (e.g., RACH forSSB0, SSB1, SSB2 in RACH slot 501 RACH for SSB3, SSB4, SSB5 in RACH slot502). Depending on the beam direction UE 115 is located from basestation 105, UE 115 may perform PRACH transmission on the RACH occasionof the associated SSB.

FIGS. 6A and 6B are block diagrams illustrating base station 105 and UE115 configured according to aspects of the present disclosure. When agap will be used between each RACH instance, the PRACH configuration maybe implemented to provide for the gap. In a first optional aspect, asillustrated in FIG. 6A, base station 105 configures RACH slots 601 and602 within autonomous PRACH window 600. Base station 105 schedules three4-symbol duration PRACH occasions in each of RACH slots 601 and 602(e.g., RACH for SSB0, SSB1, SSB2 in RACH slot 601, RACH for SSB3, SSB4,SSB5 in RACH slot 602). In performance of PRACH transmissions, UE 115may autonomously shorten the PRACH transmission to 3-symbols, leaving a1-symbol gap for LBT procedures.

In a second optional aspect, as illustrated in FIG. 6B, base station 105configures RACH slots 604 and 605 within autonomous PRACH window 603.Base station 105 schedules three 4-symbol duration PRACH occasions ineach of RACH slots 604 and 605 (e.g., RACH for SSB0, SSB1, SSB2 in RACHslot 604, RACH for SSB3, SSB4, SSB5 in RACH slot 605). Each of thescheduled PRACH occasions are scheduled to include a 1-symbol gapbetween each occasion. Thus, base station 105 configures the gaps forany LBT procedure UE 115 may perform prior to PRACH transmissions.

FIG. 7 is a block diagram illustrating a base station 105 and UE 115configured according to one aspect of the present disclosure. Within aTXOP 700, PRACH is meant for the UE which detects the control signalthat identifies the TXOP (e.g., CPDCCH, preamble, and the like). Forexample, UE 115 detects a preamble or CPDCCH that identifies TXOP 700.Base station 105, at 701, sends a trigger signal to UE 115 for PRACHtransmission within TXOP 700. The trigger signal may be included in aPDCCH signal, or the like. The RACH occasion within TXOP 700 can beconfigured semi-statically or dynamically. In detecting the controlsignal (e.g., preamble, CPDCCH), UE 115 can transmit PRACH on theallocated PRACH occasion in slot 702.

It should be noted that there may not need to be separate RACH resourcesbetween different SSBs, as in the outside TXOP PRACH configuration,because only the UEs with corresponding beams can detect the preamble,CPDCCH, etc.

FIG. 8 is a block diagram illustrating base station 105 and UE 115configured according to one aspect of the present disclosure. In a sub-6GHz carrier frequency range, control signal identifying the TXOP (e.g.,preamble, CPDCCH) can be designed to reach a majority of neighboringUEs. In such a scenario, base station 105 may want to configure a subsetof UEs to transmit PRACH within a particular TXOP to reduce the systemoverhead on PRACH resources. For example, the PRACH occasion scheduledby base station 105 within slot 802 of TXOP 800 is configured forSSB0-3. Thus, when base station 105 sends the trigger for PRACHtransmission along with the subset of SSBs-to-PRACH resource mappingwithin TXOP 800. UE 115 is located on a beam corresponding to SSB2.Therefore, when UE 115 receives the trigger signal at 801, it willtransmit PRACH in slot 802. Note, other UEs located on beams associatedwith a different subset of SSBs can be triggered to transmit PRACH atdifferent TXOPs.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

The functional blocks and modules in FIG. 4 may comprise processors,electronics devices, hardware devices, electronics components, logicalcircuits, memories, software codes, firmware codes, etc., or anycombination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure. Skilled artisans will also readilyrecognize that the order or combination of components, methods, orinteractions that are described herein are merely examples and that thecomponents, methods, or interactions of the various aspects of thepresent disclosure may be combined or performed in ways other than thoseillustrated and described herein.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another.Computer-readable storage media may be any available media that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, such computer-readable media can compriseRAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic diskstorage or other magnetic storage devices, or any other medium that canbe used to carry or store desired program code means in the form ofinstructions or data structures and that can be accessed by ageneral-purpose or special-purpose computer, or a general-purpose orspecial-purpose processor. Also, a connection may be properly termed acomputer-readable medium. For example, if the software is transmittedfrom a website, server, or other remote source using a coaxial cable,fiber optic cable, twisted pair, or digital subscriber line (DSL), thenthe coaxial cable, fiber optic cable, twisted pair, or DSL, are includedin the definition of medium. Disk and disc, as used herein, includescompact disc (CD), laser disc, optical disc, digital versatile disc(DVD), floppy disk and blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

As used herein, including in the claims, the term “and/or,” when used ina list of two or more items, means that any one of the listed items canbe employed by itself, or any combination of two or more of the listeditems can be employed. For example, if a composition is described ascontaining components A, B, and/or C, the composition can contain Aalone; B alone; C alone; A and B in combination; A and C in combination;B and C in combination; or A, B, and C in combination. Also, as usedherein, including in the claims, “or” as used in a list of itemsprefaced by “at least one of” indicates a disjunctive list such that,for example, a list of “at least one of A, B, or C” means A or B or C orAB or AC or BC or ABC (i.e., A and B and C) or any of these in anycombination thereof.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method of wireless communication, comprising:monitoring, by a user equipment (UE), for a control signal from aserving base station, wherein the control signal identifies a currenttransmission opportunity (TXOP) of the serving base station; obtaining,by the UE, an autonomous random access configuration for communicationsoutside of the current TXOP, wherein the autonomous random accessconfiguration identifies a random access slot that includes a pluralityof random access occasions; and transmitting, by the UE, in response toa failure to detect the control signal an autonomous random accesssignal in a random access occasion of the plurality of random accessoccasions corresponding to a synchronization signal block (SSB)identified by the UE for transmission.
 2. The method of claim 1, furtherincluding: performing, by the UE, a listen before talk (LBT) procedurein a gap prior to the random access occasion, wherein each random accessoccasion of the plurality of random access occasions includes acorresponding gap before the each random access occasion.
 3. The methodof claim 2, wherein the corresponding gap is one of: scheduled by theserving base station in the autonomous random access configuration, orgenerated by the UE by reducing each of the plurality of random accessoccasions by one symbol.
 4. The method of claim 1, further including:detecting, by the UE, the control signal identifying the current TXOP;receiving, by the UE, a downlink control signal including a triggersignal to send a random access signal; and transmitting, by the UE, therandom access signal in a TXOP random access occasion.
 5. The method ofclaim 4, further including: receiving, by the UE, a TXOP random accessconfiguration identifying the TXOP random access occasion within theTXOP, wherein the TXOP random access configuration is received one of:dynamically or semi-statically.
 6. The method of claim 4, wherein theTXOP random access configuration is different from the autonomous randomaccess configuration and the TXOP random access configuration replacesthe autonomous random access configuration for the UE.
 7. The method ofclaim 4, wherein the downlink control signal further includes a subsetof synchronization signal blocks (SSBs) scheduled for the TXOP randomaccess occasion of the current TXOP.
 8. The method of claim 7, whereinthe transmitting includes one of: transmitting the random access signalin the TXOP random access occasion of the current TXOP according to theSSB identified by the UE for transmission within the subset of SSBs; ortransmitting the random access signal in the TXOP random access occasionof a subsequent TXOP according the SSB identified by the UE fortransmission with a subsequent subset of SSBs scheduled for the TXOPrandom access occasion of the subsequent TXOP.
 9. An apparatusconfigured for wireless communication, comprising: means for monitoring,by a user equipment (UE), for a control signal from a serving basestation, wherein the control signal identifies a current transmissionopportunity (TXOP) of the serving base station; means for obtaining, bythe UE, an autonomous random access configuration for communicationsoutside of the current TXOP, wherein the autonomous random accessconfiguration identifies a random access slot that includes a pluralityof random access occasions; and means for transmitting, by the UE, inresponse to a failure to detect the control signal an autonomous randomaccess signal in a random access occasion of the plurality of randomaccess occasions corresponding to a synchronization signal block (SSB)identified by the UE for transmission.
 10. The apparatus of claim 9,further including: means for performing, by the UE, a listen before talk(LBT) procedure in a gap prior to the random access occasion, whereineach random access occasion of the plurality of random access occasionsincludes a corresponding gap before the each random access occasion. 11.The apparatus of claim 10, wherein the corresponding gap is one of:scheduled by the serving base station in the autonomous random accessconfiguration, or generated by the UE by reducing each of the pluralityof random access occasions by one symbol.
 12. The apparatus of claim 9,further including: means for detecting, by the UE, the control signalidentifying the current TXOP; means for receiving, by the UE, a downlinkcontrol signal including a trigger signal to send a random accesssignal; and means for transmitting, by the UE, the random access signalin a TXOP random access occasion.
 13. The apparatus of claim 12, furtherincluding: means for receiving, by the UE, a TXOP random accessconfiguration identifying the TXOP random access occasion within theTXOP, wherein the TXOP random access configuration is received one of:dynamically or semi-statically.
 14. The apparatus of claim 12, whereinthe TXOP random access configuration is different from the autonomousrandom access configuration and the TXOP random access configurationreplaces the autonomous random access configuration for the UE.
 15. Theapparatus of claim 12, wherein the downlink control signal furtherincludes a subset of synchronization signal blocks (SSBs) scheduled forthe TXOP random access occasion of the current TXOP.
 16. The apparatusof claim 15, wherein the means for transmitting includes one of: meansfor transmitting the random access signal in the TXOP random accessoccasion of the current TXOP according to the SSB identified by the UEfor transmission within the subset of SSBs; or means for transmittingthe random access signal in the TXOP random access occasion of asubsequent TXOP according the SSB identified by the UE for transmissionwith a subsequent subset of SSBs scheduled for the TXOP random accessoccasion of the subsequent TXOP.
 17. A non-transitory computer-readablemedium having program code recorded thereon, the program codecomprising: program code executable by a computer for causing thecomputer to monitor, by a user equipment (UE), for a control signal froma serving base station, wherein the control signal identifies a currenttransmission opportunity (TXOP) of the serving base station; programcode executable by the computer for causing the computer to obtain, bythe UE, an autonomous random access configuration for communicationsoutside of the current TXOP, wherein the autonomous random accessconfiguration identifies a random access slot that includes a pluralityof random access occasions; and program code executable by the computerfor causing the computer to transmit, by the UE, in response to afailure to detect the control signal an autonomous random access signalin a random access occasion of the plurality of random access occasionscorresponding to a synchronization signal block (SSB) identified by theUE for transmission.
 18. The non-transitory computer-readable medium ofclaim 17, further including: program code executable by the computer forcausing the computer to perform, by the UE, a listen before talk (LBT)procedure in a gap prior to the random access occasion, wherein eachrandom access occasion of the plurality of random access occasionsincludes a corresponding gap before the each random access occasion. 19.The non-transitory computer-readable medium of claim 18, wherein thecorresponding gap is one of: scheduled by the serving base station inthe autonomous random access configuration, or generated by the UE byreducing each of the plurality of random access occasions by one symbol.20. The non-transitory computer-readable medium of claim 17, furtherincluding: program code executable by the computer for causing thecomputer to detect, by the UE, the control signal identifying thecurrent TXOP; program code executable by the computer for causing thecomputer to receive, by the UE, a downlink control signal including atrigger signal to send a random access signal; and program codeexecutable by the computer for causing the computer to transmit, by theUE, the random access signal in a TXOP random access occasion.
 21. Thenon-transitory computer-readable medium of claim 20, further including:program code executable by the computer for causing the computer toreceive, by the UE, a TXOP random access configuration identifying theTXOP random access occasion within the TXOP, wherein the TXOP randomaccess configuration is received one of: dynamically or semi-statically.22. The non-transitory computer-readable medium of claim 21, wherein theprogram code executable by the computer for causing the computer totransmit includes one of: program code executable by the computer forcausing the computer to transmit the random access signal in the TXOPrandom access occasion of the current TXOP according to the SSBidentified by the UE for transmission within the subset of SSBs; orprogram code executable by the computer for causing the computer totransmit the random access signal in the TXOP random access occasion ofa subsequent TXOP according the SSB identified by the UE fortransmission with a subsequent subset of SSBs scheduled for the TXOPrandom access occasion of the subsequent TXOP.
 23. An apparatusconfigured for wireless communication, the apparatus comprising: atleast one processor; and a memory coupled to the at least one processor,wherein the at least one processor is configured: to monitor, by a userequipment (UE), for a control signal from a serving base station,wherein the control signal identifies a current transmission opportunity(TXOP) of the serving base station; to obtain, by the UE, an autonomousrandom access configuration for communications outside of the currentTXOP, wherein the autonomous random access configuration identifies arandom access slot that includes a plurality of random access occasions;and to transmit, by the UE, in response to a failure to detect thecontrol signal an autonomous random access signal in a random accessoccasion of the plurality of random access occasions corresponding to asynchronization signal block (SSB) identified by the UE fortransmission.
 24. The apparatus of claim 23, further includingconfiguration of the at least one processor to perform, by the UE, alisten before talk (LBT) procedure in a gap prior to the random accessoccasion, wherein each random access occasion of the plurality of randomaccess occasions includes a corresponding gap before the each randomaccess occasion.
 25. The apparatus of claim 24, wherein thecorresponding gap is one of: scheduled by the serving base station inthe autonomous random access configuration, or generated by the UE byreducing each of the plurality of random access occasions by one symbol.26. The apparatus of claim 23, further including configuration of the atleast one processor: to detect, by the UE, the control signalidentifying the current TXOP; to receive, by the UE, a downlink controlsignal including a trigger signal to send a random access signal; and totransmit, by the UE, the random access signal in a TXOP random accessoccasion.
 27. The apparatus of claim 26, further including configurationof the at least one processor to receive, by the UE, a TXOP randomaccess configuration identifying the TXOP random access occasion withinthe TXOP, wherein the TXOP random access configuration is received oneof: dynamically or semi-statically.
 28. The apparatus of claim 26,wherein the TXOP random access configuration is different from theautonomous random access configuration and the TXOP random accessconfiguration replaces the autonomous random access configuration forthe UE.
 29. The apparatus of claim 26, wherein the downlink controlsignal further includes a subset of synchronization signal blocks (SSBs)scheduled for the TXOP random access occasion of the current TXOP. 30.The apparatus of claim 29, wherein the configuration of the at least oneprocessor to transmit includes configuration of the at least oneprocessor to one of: transmit the random access signal in the TXOPrandom access occasion of the current TXOP according to the SSBidentified by the UE for transmission within the subset of SSBs; ortransmit the random access signal in the TXOP random access occasion ofa subsequent TXOP according the SSB identified by the UE fortransmission with a subsequent subset of SSBs scheduled for the TXOPrandom access occasion of the subsequent TXOP.